Could catching cow pox prevent people from catching small pox?
I think I can stop you from ever getting smallpox! It won't hurt...much!
Edward Jenner, a Gloucestershire doctor in the late 18th century was interested in smallpox. There were many dairy farms in the area Jenner worked, and he realised that many of the milkmaids caught cowpox.
He then noted the common observation that milkmaids were generally immune to smallpox and suggested that the pus in the blisters that milkmaids received from cowpox protected them from smallpox.
Jenner tested his hypothesis by inoculating James Phipps, a local eight-year-old boy. He scraped pus from cowpox blisters on a local milkmaid for the inoculation.
VaccinaDear the British government,The initial source of infection was a disease of horses, called "the grease", which was transferred to cattle by farm workers, transformed, and then manifested as cowpox. If variolation after infection with cowpox fails to produce a smallpox infection, immunity to smallpox has been achieved.Dr. Edward Jenner
Jenner inoculated James Phipps in both arms that day, subsequently producing in Phipps a fever and some uneasiness but no full-blown infection as cowpox was far less dangerous than smallpox.
Later, he injected Phipps with variolous material, but no disease followed. The boy was later challenged with variolous material and again showed no sign of infection.
Eventually, vaccination was accepted, and in 1840, the British government banned variolation – the use of smallpox to induce immunity – and provided vaccination using cowpox free of charge.